The present invention is in the field of cargo bed and bin liners and in particular in the field of devices for securing protective liners to cargo beds and bins.
The loading, transporting and unloading of cargo from the cargo bed of transport vehicles, such as dump trucks and train cargo bin cars, causes cumulative structural and finish damage to the interior cargo bed surfaces or panels, hereinafter xe2x80x9ccargo panelsxe2x80x9d. This progressively diminishes the functionality and appearance of the vehicle and can result in substantial cost being incurred for repairs and refinishing. This problem is also experienced with a variety of other cargo and materials handling vessels such as the bucket of front end loaders and backhoes and the salt bins and blades of snow plows. The exposed surfaces of such cargo and materials handling vessels are also referred to hereinafter as xe2x80x9ccargo panelsxe2x80x9d.
A number of liners and liner retainers have been developed for pickup truck beds which are disclosed in the prior art. Most of these liners and retainers relate to prefabricated liners and liner kits which are manufactured to fit a specific pickup truck bed. U. S. Pat. No. 6,203,090 B 1 to Vitoorapakorn discloses a retainer which uses a retaining plate attached to the truck bed to anchor a ring which tightens against the inside of the liner. U.S. Pat. No. 4,575,146 to Markos discloses a retainer for a pickup truck liner sidewall which attaches to the side rail of the truck bed. U.S. Pat. No. 5,131,709 to Spica discloses a liner retainer system comprising a combination of adhesive, velcro, and fasteners. U.S. Pat. No. 4,740,027 to Ormiston discloses a spring wire clip for retaining a pickup truck bed liner, the side walls of which terminate underneath the side rail. U.S. Pat. No. 4,850,633 to Emery, U.S. Pat. No. 4,595,229 to Wagner, U.S. Pat. No. 4,796,942 to Robinson, and U.S. Pat. No. 4,572,568 to Kapp et al. each disclose a fastener which secures a liner underneath the side rail without penetrating the inside surface of the liner. U.S. Pat. No. 4,906,040 to Edwards discloses a retainer clip which is inserted through a slot pair in the exterior wall of the truck bed. U.S. Pat. No. 5,100,193 to Oprea et al. discloses a clip retainer which fits the top of a specially formed liner and fits against the underside of the side rail. U.S. Pat. No. 5,046,775 to Marcum and U.S. Pat. No. 4,740,026 to Wagner disclose fasteners which extends through the outside of the truck bed and are rotated to urge against the edge of the liner which extends beneath the side rail.
The liner retainers disclosed in the patents identified are designed specifically for pickup truck cargo beds. None of these devices provides for securing field cut or plain sheet protective liners in the cargo bed of vehicles of varying dimensions, such as dump truck beds and train car beds.
There are two commonly used means of lining cargo panels of various types of vehicles. One means involves spraying on a coating of resilient material. This type of liner is designed to protect the bed from rust and scratches and to provide some protection from gouges. A second more widely used means is a drop-in liner. Drop-in liners affix to cargo panels, typically with screws and have cut-outs for cargo hooks and cleats. Typically these drop-in liners are made of plastic and are substantially thicker and more economical than spray on linings.
Drop in liners have the unfortunate drawback of curling at their ends. This undermines the protection as curling exposes parts of the cargo bed wall to load impact and elemental exposure. It also impedes the loading and unloading of the cargo.
Presently used means for anchoring protective liners to cargo panels such as bolting glueing or adhering with hook and loop fastener, are inadequate. Some user weld a flat bar to the truck bed and insert the edge of the liner under it. However, the primary means of securing liners to cargo panels is bolting the liner directly to the panels.
An objective of the present invention is to provide a retainer for securing protective liners to the cargo panels of cargo transport or handling vehicles.
A further objective of the present invention is to provide a retainer for securing protective liners to cargo panels of varying dimensions and configurations.
A further objective of the present invention is to provide a retainer for securing protective liners to cargo panels with varying slopes and intersecting angles.
A further objective of the present invention is to provide a retainer for securing field cut or field fit protective liners to cargo panels of varying dimensions and configurations.
A further objective of the present invention is to provide a retainer for securing protective liners to cargo panels which provides for sealing all edges of the liner against material or moisture intrusion.
A further objective of the present invention is to provide a retainer for securing protective liners to cargo panels which is readily removable for the removal and replacement of the protective liner.
Cargo beds of cargo handling and may consist of one or more cargo panels. The cargo bed of a flat bed truck, for instance, might have a single cargo panel, whereas, a dump truck cargo bed will have at least four cargo panels. Liners are secured to each cargo panel by embodiments of the liner retainer of the present invention. A basic retainer may be used at the outside edge of a liner. Abutting liners with different slopes can be secured with basic retainers or with concave or convex joint retainer embodiments, depending upon the angle between the abutting liners.
Protective liners placed on the cargo panels protect the panels from wear related to contact with load and weathering. The liners are prone to curl at their ends exposing the panels. The present invention prevents curling of a liner while securing the liner to the cargo panel. The present invention provides for the protection of the finish and the structural integrity of the protected cargo panel, tank or bin, and also provides for increased ease of loading, handling and dumping of material such as gravel, snow and salt, and for ease in cleaning.
The present invention may be used to protect snow plow blades, street sweepers, grader blades, sand and salt hoppers for snow removal equipment, industrial shovels, haul pack beds, belly dump beds for train car or truck, end dump truck bed, asphalt transfer rigs, grain bins and silo""s, back hoe buckets, front end loader buckets, lime silos, storage tanks, old mining equipment, thickeners, concrete ready mix trucks nix tanks and chutes.
Plastic is a preferred material for the liners, but other materials such as metal, metal alloy, wood, fiberglass and rubber may be used with the present invention. Ultra high molecular weight (UHMW) plastic, polypropylene, and high density polyethylene are preferred plastics for the liner material. Preferred embodiments of the retainer are constructed of a metal or metal alloy, but may be constructed of plastic or other resilient material.
The basic embodiment of the retainer comprises a panel attachment member for securing the retainer to a cargo panel, a liner attachment member with cleats for securing a protective liner to the retainer, and a support member for attaching the liner attachment member to the panel attachment member and for defining the thickness of liner that may be secured by the retainer by defining the separation between the panel attachment member and the liner attachment member.
The cleats can be in the form of teeth, barbs, stakes, lances, or fins. For certain preferred embodiments the cleats extend from the liner attachment member, but for other embodiments, the cleats may extend from the panel attachment member or from both the liner attachment member and the panel attachment member. For preferred embodiments, the cleats are angled inwardly, thereby facilitating the insertion of the liner in the retainer, while resisting the retraction of the liner through normal use of the cargo bed. Therefore, for preferred embodiments, the angle between the cleat axis and the liner attachment member is less than 90xc2x0 and for most liner materials and applications will be less than 90xc2x0 but more than 45xc2x0. The cleats may be made of metal or may be made or plastic or other resilient material and may be rigid or flexible.
A tapered retainer embodiment of the retainer which has a tapered support member may be used on vertical cargo panels, loader buckets and other types of cargo bins to facilitate the movement of cargo, particularly loose cargo such as gravel in a dump truck, past the retainer.
A level joint retainer embodiment which has opposing panel attachment members and opposing liner attachment members, provides for two liners to be joined and abutted together to create a continuous liner. For this embodiment, the support member connects the opposing panel attachment members and the opposing liner attachment members. This embodiment is suited for joining liners where there is no slope change.
A convex joint retainer embodiment provides for the joining and abutting of two liners at a joint which is a point of cargo panel slope change, such as that in the sloped floor of a belly dump train car. For this embodiment, the support member provides for a selected liner angle between the joined liners, which is less than 180 degrees. Similarly, a concave joint retainer embodiment provides for a liner angle which is greater than 180 degrees.
Any of the versions of the retainer, can be made with curves to fit curved exterior edges and curved joints between adjoining liner sheets.
The panel attachment member of the retainer may be attached to a cargo panel by bolting, riveting, gluing, adhering, magnetizing, welding or a combination of these methods. Self tapping screws may also be used. Other devices and methods for attaching the panel attachment member to a cargo panel will be known to persons skilled in the art.
Welding of the panel attachment member of each retainer to the cargo bed can provide an additional benefit of sealing the edge of the liner so that no moisture, cargo material or debris gets between the liner and the cargo bed. This is essential for hauling many types of cargo, such as corrosive or hazardous material. Other means of sealing the edges of the liner may be used for such applications.
There is a tendency of the liners, even the high density plastic liners, to expand and contract significantly with temperature changes. This can result in bubbling of the liner in high temperatures. Embodiments of the retainer of the present invention can be used to minimize the adverse effects of this thermal expansion and contraction. For a slide embodiment, the liner is securely attached to the panel attachment member by screws or other fasteners and is secured to the liner attachment member by cleats, but the panel attachment member is not attached to the cargo panel. This allows the panel attachment member to slide freely upon the cargo panel as the liner expands and contracts. Alternatively, for a slip embodiment, the panel attachment member is attached to the cargo panel but the liner attachment member has no cleats. This allows the edge of the liner to slide back and forth in the retainer, as the liner expands and contracts.